﻿#define _CRT_SECURE_NO_WARNINGS 1

//编程初学者入门训练第127题
//BC129 小乐乐计算函数
//https://www.nowcoder.com/practice/89238e99c36e450786ccf3a9e7481b7b?tpId=107&tqId=33410&rp=1&ru=/exam/oj/ta&qru=/exam/oj/ta&sourceUrl=%2Fexam%2Foj%2Fta%3Fpage%3D3%26tpId%3D107%26type%3D107&difficulty=undefined&judgeStatus=undefined&tags=&title=

#include <stdio.h>

float max3(int a, int b, int c) {
    int max = 0;
    if (a > b) {
        max = a;
    }
    else {
        max = b;
    }
    if (c > max) {
        max = c;
    }
    return max;
}


int main() {
    int num1, num2, num3;
    scanf("%d %d %d", &num1, &num2, &num3);

    float m = 0.0f;
    m = (float)max3(num1 + num2, num2, num3) / (max3(num1, num2 + num3, num3) +
        max3(num1, num2, num2 + num3));

    printf("%.2f", m);

    return 0;
}